A wide variety of hydrocarbon conversion processes encountered in the petroleum refining industry are catalytic in nature, and many of these processes use crystalline aluminosilicate zeolites as catalysts. Illustrative of such processes include, for example, dewaxing, hydrodewaxing, crocking, hydrocracking, alkylation, isomerization, aromatization, disproportionation and the like. Often, the products from such hydrocarbon conversion processes, or portions thereof, are admixed as blending components to form motor fuels such as gasoline.
Crystalline aluminosilicate zeolites have been used in a variety of catalysts for the conversion of hydrocarbons. Both natural and synthetic crystalline aluminosilicates have been employed. Often the zeolites comprise a noble metal such as platinum or palladium. Included among these are the Type X and Type Y zeolites, ZSM-5 and ZSM-20 zeolites, mordenite, as well as zeolite beta.
U.S. Pat. No. 3,308,069 and Re. 28,341, both issued to Wadlinger et al., disclose a method for preparing zeolite beta. The patents disclose that zeolite beta is prepared from reaction mixtures containing tetraethylammonium hydroxide as the alkali and more specifically by heating in aqueous solution a mixture of the oxides or of materials whose chemical compositions can be completely represented as mixtures of the oxides Na.sub.2 O, Al.sub.2 O.sub.3, [(C.sub.2 H.sub.5).sub.4 N].sub.2 O, SiO.sub.2 and H.sub.2 O suitably at a temperature of about 75.degree.-200.degree. C. until crystallization occurs. The product which crystallizes from the hot reaction mixture is separated, suitably by centrifuging or filtration, washed with water and dried. The material so obtained may be calcined by heating in air or an inert atmosphere at a temperature in the approximate range of 400.degree.-1700.degree. F. or higher so long as the temperature is not sufficient to destroy the crystallinity.
U.S. Pat. No. 4,642,226, issued to Calvert et al., relates to a new and improved form of crystalline silicate having the structure of zeolite beta, to a new and useful improvement in synthesizing said crystalline silicate and to the use of said crystalline silicate as a catalyst for organic compound, e.g., hydrocarbon compound, conversion. The patent discloses the use of dibenzyldimethylammonium as a directing agent, i.e., templating agent, instead of tetraethylammonium hydroxide as described above. The patent further discloses that the zeolite beta can be ion-exchanged by conventional techniques with a salt solution. Following contact with the salt solution of the desired replacing cation, the zeolite is then preferably washed with water and dried at a temperature ranging from 65.degree. to about 315.degree. C. and thereafter may be calcined in air or other inert gas at temperatures ranging from about 200.degree. to about 600.degree. C., preferably from about 200.degree. to about 550.degree. C. for periods of time ranging from 1 to 48 hours or more to produce a catalytically active thermal decomposition product thereof. The patent discloses the use of zeolite beta in hydroisomerization of normal paraffins, when provided with a hydrogenation component, e.g., platinum.
U.S. Pat. No. 4,428,819, issued to Shu et al., discloses a process relating to the hydroisomerization of catalytically dewaxed lubricating oils using zeolite beta. The patent discloses that when the zeolites have been prepared in the presence of organic cations they are catalytically inactive, possibly because the intracrystalline free space is occupied by organic cations from the forming solution. It is further disclosed that the zeolites may be activated by heating in an inert atmosphere at 540.degree. C. for one hour, for example, followed by base exchange with ammonium salts followed by calcination at 540.degree. C. in air.
U.S. Pat. No. 4,554,145, issued to Rubin, discloses a method for the preparation of zeolite beta. In similar fashion to above cited U.S. Pat. No. 4,642,226, the patent discloses that the synthesized zeolite beta can be ion-exchanged with a salt and thereafter calcined in air or other inert gas at temperatures ranging from about 200.degree.-550.degree. C. for periods of time ranging from 1 to 48 hours or more to produce a catalytically active thermal decomposition product thereof. The patent discloses the use of zeolite beta in hydroisomerization of normal paraffins, when provided with a hydrogenation component, e.g., platinum.
U.S. Pat. No. 4,612,108 issued to Angevine et al., describes a hydrocracking process for feedstocks containing high boiling, waxy components using a number of sequential beds of hydrocracking catalyst based on zeolite beta. The proportion of zeolite beta in the catalyst increases in sequence so that the final bed has the highest zeolite concentration. The dewaxing activity of the zeolite beta-containing catalysts is stated to be enhanced by the use of sequential beds in this manner. The pour point of the high boiling fraction is reduced, as well as that of the distillate product, permitting part of the high boiling fraction to be included in the distillate product, thereby increasing the useful distillate yield.
U.S. Pat. No. 4,568,655, issued to Oleck et al. discloses a single catalyst system which is capable of demetalizing, hydrotreating and hydrodewaxing petroleum residue in a single stage process. The catalyst system utilized includes one or more metal oxides or sulfides of Group VIA and Group VIII of the periodic table impregnated on a base of refractory oxide material and zeolite beta. The catalyst also has about 75% of its pore volume in pores no greater than 100 .ANG. units in diameter and about 20% of its pore volume in pores greater than about 300 .ANG. units in diameter.
U.S. Pat. No. 4,301,316 issued to Young, relates to a process for the selective alkylation of substituted or unsubstituted benzene compounds with relatively long chain length alkylation agents to produce phenylalkanes having an improved yield of the more external phenyl isomers. The reaction can be carried out in the presence of a crystalline zeolite catalyst such as zeolite beta.
U.S. Pat. No. 4,501,926, issued to LaPierre et al., discloses that petroleum distillate feedstocks may be effectively dewaxed by isomerizing the waxy paraffins without substantial cracking. The isomerization is carried out over zeolite beta as a catalyst and may be conducted either in the presence or absence of added hydrogen. The catalyst may include a hydrogenation/dehydrogenation component such as platinum or palladium in order to promote the reactions which occur. The hydrogenation/dehydrogenation component may be used in the absence of added hydrogen to promote certain hydrogenation/dehydrogenation reactions which will take place during the isomerization.
U.S. Pat. No. 4,518,485, issued to LaPierre et al., relates to a process for dewaxing a hydrocarbon feedstock with a relatively high pour point and containing paraffins selected from the group of normal paraffins and slightly branched paraffins and sulfur and nitrogen compounds which comprises subjecting said oil to hydrotreating in a hydrotreating zone operated at hydrotreating conditions sufficient to remove at least a portion of said sulfur and nitrogen compounds and subjecting said hydrotreated oil to catalytic dewaxing by contacting said oil with a catalyst comprising zeolite beta having a silica/alumina ratio of at least 30:1 and a hydrogenation component under isomerization conditions.
U.S. Pat. No. 4,554,065, issued to Albinson et al. describes a process for dewaxing a hydrocarbon feedstock with a relatively high pour point and containing paraffins selected from the group of normal paraffins and slightly branched paraffins which comprises subjecting said feedstock to catalytic dewaxing at catalytic dewaxing conditions by passing said feedstock, along with hydrogen, over a dewaxing catalyst comprising zeolite beta having a noble metal hydrogenation/dehydrogenation component to produce a partially dewaxed product and subjecting said partially dewaxed product to catalytic dewaxing at catalytic dewaxing conditions by passing said partially dewaxed product over a catalyst comprising zeolite beta having a base metal hydrogenation/dehydrogenation component to recover a substantially dewaxed product as a product of the process.
European Patent Application No. 0 159 846, European Patent Application No. 0 164 939 and European Patent Application No. 0 164 208 disclose particular preparation methods of zeolite beta and the use of zeolite beta in hydroisomerization of normal paraffins, when provided with a hydrogenation component, e.g., platinum.
U.S. Pat. No. 4,647,368, issued to McGuiness et al., describes an upgrading process for paraffinic naphthas which subjects a full range naphtha to hydrocracking over a zeolite beta hydrocracking catalyst to effect a selective partial hydrocracking in which the higher molecular weight n-paraffinic components of the naphtha are hydrocracked preferentially to the lower molecular weight components with concurrent isomerization of n-paraffins to isoparaffins, to form a hydrocracked effluent which comprises isobutane, C.sub.5 -C.sub.7 paraffins and relatively higher boiling naphthenes and paraffins. The hydrocracked effluent is split to remove the isobutane and the C.sub.5 and C.sub.7 paraffins with the balance of the higher boiling components being used as a reformer feed. Removal of the C.sub.5 and C.sub.7 paraffins permits improved reformer operation with the production of a higher octane product. The isomerization of the paraffins which occurs in the hydrocracking step provides a C.sub.5 -C.sub.7 paraffinic fraction which is of relatively higher octane number because of the shift to isoparaffins, permitting this component to be used as a gasoline blending component.
U.S. Pat. No. 4,845,063, issued to Chu, teaches a zeolite containing a metal of Group IB which preferably is silver. The zeolite may be activated by heating in an inert atmosphere at 540.degree. C., ammonium-exchanged followed by calcination at 540.degree. C. in air. After loading with silver the zeolite is calcined at 540.degree. C. to 900.degree. C., preferably at 750.degree. C. to 875.degree. C.
U.S. Pat. No. 5,011,805, issued to Dessau, discloses a non-acidic reforming catalyst containing zeolite beta and a Group VIII metal which preferably is platinum. The zeolite containing the Group VIII metal is subjected to thermal treatment at a temperature between 150.degree. and 500.degree. C.
It can be seen from the disclosures of the above-cited patents that zeolite beta has been prepared for use as a catalyst in various hydrocarbon-conversion processes. However, none of the references disclose zeolite beta having the unique characteristics of the present invention which provide particular utility in hydrocarbon-conversion processes.